Rolls for twisting drills.



S. DENK.

ROLLS FOR TWISTING DRILLS.

APPLIOATION FILED FEB. 2-, 1903.

m: Noam ravens co. mama PATENTED JUNE 7, 1904;

UNITED STATES Patented June 7, 1904.

PATENT @FFIQE.

SIMON DENK, OF VVI-IITESTONE, NEW YORK, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, OF TWO-THIRDS TO LOUIS O. TAFEL, OF BROOK- LYN, NEWV YORK.

SPECIFICATION forming part of Letters Patent No. 761,880, dated June 7, 1904,

Application filed February 2, 1903. Serial No. 141,455- (No model.)

To (ZZZ whom, it nuty concern:

Be it known that I, SIMON DENK, a citizen of the UnitedStates, residing in Whitestone, in the county of Queens and State of New York, have invented certain new and useful Improvements in Rolls for Twisting Drills, of which the following is a specification.

This invention relates to rolls .for twisting fluted rods or blanks to form twist-drills.

It has been proposed to form, as by forging, suitable straight grooves of flutes lengthwise of cylindrical rods and then to runthe grooved rods between disk-like rolls, which are set at an angle to each other and are adapted to said flutes for giving a twist to the grooves, so as to produce a twist-drill. The rolls are intended to work upon axes which are in parallel planes; but the axes are each at an angle to the. drill of about fifteen to twenty degrees and at an angleto each other of about thirty to forty degrees. 'Many attempts have been made to produce satisfactory drills in this way; but although it has been found possible to effect a twist in the article, still a drill that is satisfactory or mar ketable has not been produced, partly because the rod, which-is heated at the rolling operation, becomes distorted and misshapen by the rolls and partly because the side of the groove which is intended to form the straight radial cutting-lip of the tip of the finished drill becomes so misshapened from the lateral pres,

to be largely due to the inefficiency of the rolls in guiding or controlling the drill as it feeds therebetween.

The object of my invention is to overcome these difliculties and to provide rolls which will produce marketable drills.

In the drawings forming part of this specification, Figure 1 is a plan showing a drill .the drill-rod.

feeding between my novel rolls, the lower roll being shown in full lines and the upper roll in dotted lines. Fig. 2 is a vertical section taken on the line 50 m of Fig. 1 in the plane of the axis of the lower roll. Fig. 3 is an elevation showing a drill entered between the re ls.

The upper and lower rolls 1 and 2 are mounted upon power-driven arbors or axles 3 and 4, respectively, these being preferably hori- Zontal. The upper axle and roll may lie at an angle of about thirty degrees or more to the lower axle and roll, as will be understood from an examination of Fig. 1. The upper roll has a circumferential ridge 5 and the lower roll a ridge 6 for engaging within the opposite flutes 7 and 8 in the drill-blank, these ridges being suitably rounded or shaped, so as to match or nearly match the grooves. The upper roll 1 is placed at such a point over the lower roll2 that a vertical line intersecting the axes of both rolls passes through the centers or crowns of both ridges 5 and 6, as will be understood by reference to Figs. 1 and 2. These ridges by reason of their crosswise arrangement become the principal factors in twisting the drill-rod 9, which is drawn horizontally between the rolls at an angle of about fifteen or more degrees to each of the latter, as will be understood by reference to Fig. 1.

The movement of the drill may be effected by the grip of the rolls thereon, these being power-driven and rotating in unison.

Referring now to the lower roll 2, it will be seen that it is provided with a conical or flaring flange 10, which forms a shallow concave outward curve from the base 11 of one flank of the ridge 6, the purpose of this flange being to afford a support or guide for one side 12 of Upon the opposite flank of the ridge 6 is formed a flaring flange 13, which may also be slightly concaved and may be more abrupt than the flange 10 and preferably does not extend so deeply into the roll, the inner termination of said flange or its junction with the flank of the ridge beingindicated at 1 1. In other words, the flank or side of the ridge 6 which joins the flange 13 is preferably not so deep as the side which joins the ridge 10, as clearly seen at Fig. 2. The flange 113 is also intended to assist in guiding the c rill.

The upper roll is similar to the lower roll, being provided with a flange 15,corresponding to the lower flange 10, and also with a flange 16. corresponding to the lower flange 13; but it will be noted that the rolls are placed reversely, so that the flange 16 overlies the flange l0 and the flange 15 overlies the flange 13, thereby producing like effects upon diametrically opposite sides of the drill-rod as it feeds between the rolls.

Referring to Fig. 1, it will be perceived that the diameter of each flange is preferably greater than that of the ridge, and it will also be understood that the drill contacts with the flange 10 as far out as the vicinity of the point 17 and contacts with the flange 13 as far as in the vicinity of the point marked 18, besides contacting with said flanges at intermediate points and also with the central ridge 6, while the drill upon its upper side is similarly engaged by the flanges and ridges upon the upper roll. It will be observed that the points 17 and 18 are considerably separated. Owing to its being supported at so many points and :for such a distance, the liability of the drillrod to make erratic movements as it feeds through the rolls is wholly obviated and the drills come out from the rolls straight and true. Each of the flanges 10 and 13 cooperates independently with the ridge 6 in guiding or controlling the drill, and the same is true of the flanges upon the upper roll, and while I prefer to use both flanges upon each roll, still my invention is not limited to rolls each having two flanges, so long as a flange upon one roll supports the drill upon a side diametrically opposite to the side of the rod which is supported by a like flange upon the other roll-that is, so long as the rolls have reverse arrangement.

The ridges 5 and 6 are suitably formed to nearly fit the original grooves 19, formed in the drill-blanks, and so as to accord with the final forming of the grooves desired. It will be understood that the twisting of the drill is effected by the lateral pressure of the ridges within the grooves of the drill-blanks, and where the ridges alone are depended upon to effect the twisting this lateral pressure usually has the efleet of inisshaping the drill; but by provision of the drill-supporting flanges 10, 13, 15, and 16 this difficulty is minimized or avoided.

Preferably the groove at 11 is so deep as not to contact with the drill edge 20, this being the advance or cutting edge of the spiral. One of the principal advantages of my improvements resides in the practicability of turning out drills so grooved that straight cutting edges or lips generate upon their tips when the drills are pointed after the usual manner of twist-drills. This end is accomplished partly by having the side of the ridge 6 of the proper form and partly by suitably supporting the drill independently of said ridge, as by-means of the flanges 10 and 15.

Preferably the flanges 13 and 16 are formed to produce a slight relief upon the peripheral spirals of the drill, as from about the line 21, Fig. 1, to the idle edge 22 of the spiral. The flange 13 therefore performs the twofold function of a support and a former for the drill, and the latter is rendered practically ready for use upon the completion of the twisting operation, the necessity of subsequently grinding a relief upon the drill being avoided. It will be understood that the flange 16 likewise relieves the other spiral of the drill.

It will be understood that variations in the form and disposition of the parts may be resorted to within the scope of my invention. For instance, if a variation is made only in the diameter of the rolls corresponding variations may be made in the curvatures of the ridges and flanges. The same is true as to variations in the angles of the rolls or of the angle of the twist to be given the drills.

Having thus described my invention, I claim 1. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge for engaging the drill-flutes, each ridge being flanked upon each side with a drill-supporting flange.

2. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge of rounded section for engaging the d rillflutes, each ridge being flanked upon each side with a flaring drill-supporting flange.

3. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge of rounded section for engaging the d rillflutes, flanked upon each side with a flaring drill-su iporting flange, at least one flange upon each roll being slightly concave, and the rolls being placed one reversely to the other, so that said flanges engage the drill-rod upon diametrically opposite sides thereof.

4. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge of rounded section for engaging the dri llflutes, said ridge being flanked upon each side with a concave flaring drill-supporting flange.

5. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a ClICUInfOl'Gl'illlfll ridge of rounded section for engaging the d rillflutes, flanked upon each side with a concave flaring drill-supporting flange, one of the flanges upon each roll being formed for rolling a relief upon the drill-spiral.

6. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge of rounded section for engaging the drillflutes, a flaring drill-supporting flange being provided upon one flank of each ridge, and the rolls being placed one reversely to the other, so that said flanges engage the drill upon diametrically opposite sides of the latter.

7. A roll having a peripheral rounded ridge, as 6, a flange, as 10, flaring from the base of said ridge upon one flank thereof, and a flange, as 13, flaring from the base of said ridge upon the other flank thereof; said ridge being adapted for insertion in the flute of adrill-rod which is of such a size as to be suitably supported by 1slaid flanges at the operation of twisting the cm 8. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge for engaging the drill-flutes, each ridge being flanked upon each side with a drill-supporting flange, and the diameter of the flanges being at least as great as the diameter of the ridge.

9. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge of rounded section for engaging the drillflutes, each ridge being flanked upon each side with a flaring drill-supporting flange, and the diameter of each flange exceeding the diameter of the ridge.

10. In a machine for twisting fluted drillrods, a pair of rolls mounted at an angle to each other and each having a circumferential ridge of rounded section for engaging the drillflutes, a flaring drill-supporting flange being provided upon one flank of each ridge, the diameter of the flange exceeding that of the ridge, and the rolls being placed one reversely to the other, so that said flanges engage the drill upon diametrically opposite sides of the latter.

SIMON DENK. I/Vitnesses:

ANTONIO BUoN, HENRY S. HUND. 

